Up until now, there has been proposed an automotive vehicle which comprises a driving source such as an internal combustion engine, an electric motor and the like, and vehicle wheels drivably connected with the driving source through a power transmission train to enable the driving force from the driving source to be transmitted to the vehicle wheels through the power transmission train. The power transmission train with which the driving source is drivably connected is apt to generate a muffled sound and a “jara sound” originated for example from the rotation fluctuation caused by the torque fluctuation of the internal combustion engine.
The term “jara sound” is intended to indicate an abnormal sound generated by the idling gear couples of the transmission gear couples collided by torsional vibrations originated from the rotation fluctuation caused by the torque fluctuation of the internal combustion engine. The term “muffled sound” is intended to indicate an abnormal sound generated in the passenger room by the vibrations caused by the torsional resonance of the power transmission train having the torque fluctuation of the internal combustion engine as a vibratory force.
There has so far been known a torsional vibration damping apparatus which is constructed to have a driving source such as an internal combustion engine, an electric motor and the like drivably connected with vehicle wheels to transmit the driving force from the driving source to the vehicle wheels through a power transmission train having transmission gear sets and to absorb torsional vibrations generated between the driving source and the power transmission train.
As a torsional vibration damping apparatus, there is, for example, an apparatus which comprises a hub member drivably connected with the input shaft of the transmission, a disc plate having a clutch disc to be selectively engaged with or disengaged from a flywheel at the side of the driving source, and resilient members resiliently connecting the hub member and the disc plate and equi-distantly provided in the circumferential direction of the hub member and the disc plate (e.g., see Patent Document 1).